Sequence-Dependent Repolarization Is Modulated by Endogenous Action Potential Duration Gradients Rather Than Electrical Coupling in Ventricular Myocardium.

Background: Previous studies suggest the relationship between activation time (AT) and action potential duration (APD) in the heart is dependent on electrotonic coupling, but this has not been directly tested. This study assessed whether acute changes in electrical coupling, or other determinants of conduction or repolarization, modulate APD heterogeneity.

Methods And Results: Langendorff-perfused guinea pig hearts were epicardially paced and optically mapped after treatment with the gap junction uncoupler carbenoxolone, ephaptic uncoupler mannitol, ephaptic enhancer dextran 2MDa, sodium channel inhibitor flecainide, or rapid component of the delayed rectifier potassium channel inhibitor E4031.

Impacts of Thunderstorm-Generated Gravity Waves on the Ionosphere-Thermosphere Using TIEGCM-NG/MAGIC Simulations and Comparisons With GNSS TEC, ICON, and COSMIC-2 Observations.

We use the TIEGCM-NG nudged by MAGIC gravity waves to study the impacts of a severe thunderstorm system, with a hundred tornado touchdowns, on the ionospheric and thermospheric disturbances. The generated waves induce a distinct concentric ring pattern on GNSS TIDs with horizontal scales of 150-400 km and phase speeds of 150-300 m/s, which is well simulated by the model. The waves show substantial vertical evolution in period, initially dominated by 0.

Different Behavior of Density Perturbations Between Dayside and Nightside in the Martian Thermosphere and the Ionosphere Associated With Atmospheric Gravity Waves.

To investigate the excitation mechanism of ionospheric perturbations on Mars by the Neutral Gas and Ion Mass Spectrometer (NGIMS) onboard Mars Atmosphere and Volatile EvolutioN (MAVEN), we categorize ionospheric perturbations into three cases: (a) the ion-neutral coupling cases where ion and neutral perturbations are well coupled, (b) the ion-specific cases where ion perturbations move independently from neutrals, and (c) the coronal mass ejection cases associated with solar wind extreme events. A representative number of cases from total profiles are compared with a numerical model to determine the fraction that can be explained by an atmospheric gravity waves (GW). The neutral perturbations on the dayside at 170-190 km altitudes are in excellent agreement with the GW.

Satellite-Derived, Smartphone-Delivered Geospatial Cholera Risk Information for Vulnerable Populations.

Cholera, an acute waterborne diarrheal disease, remains a major global health challenge. Despite being curable and preventable, it can be fatal if left untreated, especially for children. Bangladesh, a cholera-endemic country with a high disease burden, experiences two peaks annually, during the dry pre-monsoon spring and the wet post-monsoon fall seasons.

Habitat suitability of biocrust communities in a cold desert ecosystem.

Drylands are unique among terrestrial ecosystems in that they have a significant proportion of primary production facilitated by non-vascular plants such as colonial cyanobacteria, moss, and lichens, i.e., biocrusts, which occur on and in the surface soil.

Size-dependence of food intake and mortality interact with temperature and seasonality to drive diversity in fish life histories.

Understanding how growth and reproduction will adapt to changing environmental conditions is a fundamental question in evolutionary ecology, but predicting the responses of specific taxa is challenging. Analyses of the physiological effects of climate change upon life history evolution rarely consider alternative hypothesized mechanisms, such as size-dependent foraging and the risk of predation, simultaneously shaping optimal growth patterns. To test for interactions between these mechanisms, we embedded a state-dependent energetic model in an ecosystem size-spectrum to ask whether prey availability (foraging) and risk of predation experienced by individual fish can explain observed diversity in life histories of fishes.

Novel phenylthiazoles with a -butyl moiety: promising antimicrobial activity against multidrug-resistant pathogens with enhanced ADME properties.

The structure-activity relationship of a new -butylphenylthiazole series, with a pyrimidine linker, was investigated. We wished to expand knowledge of this novel class of antibiotics by generating 21 new derivatives bearing ≥2 heteroatoms in their side chains. Their activity was examined against isolates of methicillin-resistant (MRSA), , , , and .

Naphthylthiazoles: a class of broad-spectrum antifungals.

Cryptococcal infections remain a major cause of mortality worldwide due to the ability of to pass through the blood-brain barrier (BBB) causing lethal meningitis. The limited number of available therapeutics, which exhibit limited availability, severe toxicity and low tolerability, necessitates the development of new therapeutics. Investigating the antifungal activity of a novel series of naphthylthiazoles provided -diaminocyclohexyl derivative 18 with many advantageous attributes as a potential therapeutic for cryptococcal meningitis.

Chigger mite () ectoparasitism does not contribute to sex differences in growth rate in eastern fence lizards ().

Parasitism is nearly ubiquitous in animals and is frequently associated with fitness costs in host organisms, including reduced growth, foraging, and reproduction. In many species, males tend to be more heavily parasitized than females and thus may bear greater costs of parasitism. is a female-larger, sexually size dimorphic lizard species that is heavily parasitized by chigger mites ().

Multiscale variability in nutrients and secondary metabolites in a bat-dispersed neotropical fruit.

Ripe fleshy fruits contain not only nutrients but also a diverse array of secondary metabolites. Nutrients serve as a reward for mutualists, whereas defensive metabolites protect the fruit against pests and predators. The composition of these chemical traits is highly variable, both across different plants and even within repeating structures on the same individual plant.

Exploring novel aryl/heteroaryl-isosteres of phenylthiazole against multidrug-resistant bacteria.

Antimicrobial resistance has become a concern as a worldwide threat. A novel scaffold of phenylthiazoles was recently evaluated against multidrug-resistant to control the emergence and spread of antimicrobial resistance, showing good results. Several structural modifications are needed based on the structure-activity relationships (SARs) of this new antibiotic class.

A new species of from southern California (Siphonophorida, Siphonorhinidae).

The millipede fauna inhabiting deep soil are poorly known. They are small and threadlike, slow moving, lacking pigmentation, and rarely encountered due to their obscure underground way of life. One family, the Siphonorhinidae, encompasses four genera and 12 species in a fragmentary distribution in California, southern Africa, Madagascar, the Malay Archipelago, and Indo-Burma.

Assessing opportunities and inequities in undergraduate ecological forecasting education.

Conducting ecological research in a way that addresses complex, real-world problems requires a diverse, interdisciplinary and quantitatively trained ecology and environmental science workforce. This begins with equitably training students in ecology, interdisciplinary science, and quantitative skills at the undergraduate level. Understanding the current undergraduate curriculum landscape in ecology and environmental sciences allows for targeted interventions to improve equitable educational opportunities.

Genome-wide association analysis of hyperspectral reflectance data to dissect the genetic architecture of growth-related traits in maize under plant growth-promoting bacteria inoculation.

Plant growth-promoting bacteria (PGPB) may be of use for increasing crop yield and plant resilience to biotic and abiotic stressors. Using hyperspectral reflectance data to assess growth-related traits may shed light on the underlying genetics as such data can help assess biochemical and physiological traits. This study aimed to integrate hyperspectral reflectance data with genome-wide association analyses to examine maize growth-related traits under PGPB inoculation.

Expanding the structure-activity relationships of alkynyl diphenylurea scaffold as promising antibacterial agents.

With the continuous and alarming threat of exhausting the current antimicrobial arsenals, efforts are urgently needed to develop new effective ones. In this study, the antibacterial efficacy of a set of structurally related acetylenic-diphenylurea derivatives carrying the aminoguanidine moiety was tested against a panel of multidrug-resistant Gram-positive clinical isolates. Compound 18 was identified with a superior bacteriological profile than the lead compound I.

DNA release from plant tissue using focused ultrasound extraction (FUSE).

Premise: Sample preparation in genomics is a critical step that is often overlooked in molecular workflows and impacts the success of downstream genetic applications. This study explores the use of a recently developed focused ultrasound extraction (FUSE) technique to enable the rapid release of DNA from plant tissues for genetic analysis.

Methods: FUSE generates a dense acoustic cavitation bubble cloud that pulverizes targeted tissue into acellular debris.

Population genetic structure of the globally introduced big-headed ant in Taiwan.

Global commerce and transportation facilitate the spread of invasive species. The African big-headed ant, (Fabricius), has achieved worldwide distribution through globalization. Since the late 19th century, Taiwan has served as a major seaport because of its strategic location.

Associations Between Surface Mining Airsheds and Birth Outcomes in Central Appalachia at Multiple Spatial Scales.

A considerable body of research exists outlining ecological impacts of surface coal mining, but less work has explicitly focused on human health, and few studies have examined potential links between health and surface coal mining at fine spatial scales. In particular, relationships between individual birth outcomes and exposure to air contaminants from coal mining activities has received little attention. Central Appalachia (portions of Virginia, West Virginia, Kentucky, and Tennessee, USA), our study area, has a history of resource extraction, and epidemiologic research notes that the region experiences a greater level of adverse health outcomes compared to the rest of the country that are not fully explained by socioeconomic and behavioral factors.

Observations of Atmospheric Tides in the Middle and Upper Atmosphere of Mars From MAVEN and MRO.

Variability in the Martian upper atmosphere is strongly linked to the lower atmosphere and much of it can be attributed to vertical wave propagation. Atmospheric tides in particular are a well-known phenomenon in the Martian atmosphere that play a key role in the transport of energy as they propagate to higher altitudes. Previous theoretical predictions and observations suggest that tides producing wavenumber-2 and wavenumber-3 patterns are strongest in a fixed local time at high altitudes, however, the energy they carry and the region of deposition are not well characterized.

Neutral Composition Information in ICON EUV Dayglow Observations.

Since the earliest space-based observations of Earth's atmosphere, ultraviolet (UV) airglow has proven a useful resource for remote sensing of the ionosphere and thermosphere. The NASA Ionospheric Connection Explorer (ICON) spacecraft, whose mission is to explore the connections between ionosphere and thermosphere utilizes UV airglow in the typical way: an extreme-UV (EUV) spectrometer uses dayglow between 54 and 88 nm to measure the density of O, and a far-UV spectrograph uses the O 135.6 nm doublet and N Lyman-Birge-Hopfield band dayglow to measure the column ratio of O to N in the upper thermosphere.

Vibrational spectroscopy investigation of defects in Zr- and Hf-UiO-66.

Defect engineering in metal-organic framework compounds has allowed for improvements in catalysis-based functionalities, gas sensing, and gas storage. Metal-organic framework UiO-66 compounds with Zr- and Hf-based metal secondary building units were studied with Raman and infrared vibrational spectroscopy. Missing linker and missing cluster defects were engineered into the crystal structure a modulated synthesis technique.

Multiresolution Modeling of High-Latitude Ionospheric Electric Field Variability and Impact on Joule Heating Using SuperDARN Data.

The most dynamic electromagnetic coupling between the magnetosphere and ionosphere occurs in the polar upper atmosphere. It is critical to quantify the electromagnetic energy and momentum input associated with this coupling as its impacts on the ionosphere and thermosphere system are global and major, often leading to considerable disturbances in near-Earth space environments. The current general circulation models of the upper atmosphere exhibit systematic biases that can be attributed to an inadequate representation of the Joule heating rate resulting from unaccounted stochastic fluctuations of electric fields associated with the magnetosphere-ionosphere coupling.

A revision of the species group in the millipede genus Chamberlin, 1918 (Diplopoda, Polydesmida, Xystodesmidae).

Although many new species of the millipede genus Chamberlin, 1918 have been known from museum collections for over half a century, a systematic revision has not been undertaken until recently. There are two species groups in the genus: the species group and the species group. In this study, the species group was investigated.

A conformational role for NifW in the maturation of molybdenum nitrogenase P-cluster.

Reduction of dinitrogen by molybdenum nitrogenase relies on complex metalloclusters: the [8Fe:7S] P-cluster and the [7Fe:9S:Mo:C:homocitrate] FeMo-cofactor. Although both clusters bear topological similarities and require the reductive fusion of [4Fe:4S] sub-clusters to achieve their respective assemblies, P-clusters are assembled directly on the NifDK polypeptide prior to the insertion of FeMo-co, which is fully assembled separately from NifDK. P-cluster maturation involves the iron protein NifH as well as several accessory proteins, whose role has not been elucidated.

Public responses to COVID-19 case disclosure and their spatial implications.

We study how the public changes their mobility and retail spending patterns as precautionary responses to the disclosed location of COVID-19 cases. To look into the underlying mechanisms, we investigate how such change varies spatially and whether there is any spatial spillover or substitution. We use the daily data of cell phone-based mobility and credit card transactions between February 10 and May 31 in both 2019 and 2020 in Seoul, South Korea, and employ the empirical approach analyzing the year-over-year percent change for the mobility and consumption outcomes.